This invention relates to loudspeaker systems intended for use in motor vehicles and particularly to a sound bar assembly that can be mounted against the roof of the vehicle. The sound bar assembly contains chambers and other structure to enhance the quality of the sound and improve the aesthetic appearance of the vehicle interior.
For many years loudspeaker systems for motor vehicles consisted of speakers mounted in the instrument panel where they directed sound against the windshield. These systems relied on the windshield to direct the sound to the vehicle occupants. Speakers similarly were mounted in the package shelf behind the rear seat of the vehicle where they directed sound against the rear window of the vehicle and relied on the rear window to direct sound to the occupants.
Technical progress resulted in mounting speakers in the front doors of the vehicle. This location utilized space more effectively and enabled aiming the sound somewhat more directly at the vehicle occupants. Rear speakers were located in the rear doors or in the sides of the rear utility area of utility vehicles. While these arrangements resulted in improved sound quality, other hardware in the doors required mounting the speakers in the lower portions of the doors where the sound was directed more at the legs, and only indirectly at the ears, of the occupants. Speakers in the utility area of utility vehicles frequently were covered by articles being transported by the vehicle that distorted, muffled, or even blocked the sound completely.
An early expression of technology for mounting speakers against the roof of the vehicle appeared in 1939 with U.S. Pat. No. Little 2,165,637. Several additional patents on individual overhead speakers issued in the '70s to Okamoto et al. U.S. Pat. No. 4,005,761 and Okamoto et al. U.S. Pat. No. 4,056,165. Auto makers did not begin to appreciate the advantages of these speaker locations until the '80s when sound bar assemblies that extended across the roof of the vehicle and that included two or more speakers began to appear in the patent art and in motor vehicles. Several recent inventions in sound bar assemblies are shown in US Pat. Nos. Koppelomaki 4,673,056, Rosen 5,094,316, and Bahm et al. 5,606,623.